1. Field of the Invention
The present disclosure generally relates to information processing and, more particularly, to a display technology in which a plurality of information processing apparatuses each having a communication mechanism and a display unit are used to display an image.
2. Description of the Related Art
Tablet personal computers (PCs) are rapidly gaining popularity for their handiness. Even conference systems that use tablet PCs have recently been proposed. Such conference systems help in going paperless. Most tablet PCs have a display screen sized around 10 inches, and therefore are not suitable for displaying a complicated blueprint, a map, or other similar images where checking the overall image and detailed partial images simultaneously is desired. As a solution, a technology of treating a plurality of information processing apparatuses as one information processing apparatus to display pieces of a large image on the plurality of information processing apparatuses in a distributed manner.
Japanese Patent Application Laid-Open No. 11-134087 discloses a display system in which a plurality of devices each having a display unit are arranged so as to be capable of providing a large screen as a whole. This display system accomplishes large-screen display as a whole by combining a plurality of display units. Specifically, one device keeps track of the positions of all devices and controls image display of each device.
Japanese Patent Application Laid-Open No. 2010-266752 discloses a display device that has a foldable display unit. This display device has an acceleration sensor and switches the direction and display size of an image in a folded mode and a large-screen mode, depending on the result of detection by the acceleration sensor.
When displaying one image with display units of a plurality of tablet PCs, it is crucial to precisely determine for each tablet PC which part of the whole image is displayed by the display unit of the tablet PC. Unless this determination is made precisely, correct display of the whole image with a plurality of display units cannot be achieved. It is therefore necessary to know the accurate position of each tablet PC in the entire screen by detecting for each tablet PC in which part the tablet PC is coupled to another tablet PC.
In Japanese Patent Application Laid-Open No. 11-134087, a special sensor for detecting the physical contact state of each device is required for determining which of the plurality of devices displays which part of the whole image. A high-precision position sensor is also needed in order to detect the positions of the devices relative to one another. Neither sensor is mounted to tablet PCs that are commonly available at present. If the sensors were to be mounted to a tablet PC, the tablet PC would be expensive.
Japanese Patent Application Laid-Open No. 2010-266752 deals with a foldable and large-screen information processing apparatus in which each display unit constituting a large screen is assigned in advance a part of the whole image to display. Accordingly, this cannot be applied to a case where a plurality of tablet PCs are used to constitute one information processing apparatus.